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| 1 | +using System; |
| 2 | +using System.Collections.Generic; |
| 3 | +using System.Linq; |
| 4 | +using System.Text; |
| 5 | +using System.Security.Cryptography; |
| 6 | + |
| 7 | +namespace AuthorizeNet |
| 8 | +{ |
| 9 | + /// <summary> |
| 10 | + /// Source Code from MSDN article http://msdn.microsoft.com/en-us/magazine/cc163367.aspx |
| 11 | + /// </summary> |
| 12 | + public class CryptoRandom |
| 13 | + { |
| 14 | + private RNGCryptoServiceProvider _rng = |
| 15 | + new RNGCryptoServiceProvider(); |
| 16 | + private byte[] _uint32Buffer = new byte[4]; |
| 17 | + |
| 18 | + public CryptoRandom() { } |
| 19 | + public CryptoRandom(Int32 ignoredSeed) { } |
| 20 | + |
| 21 | + public Int32 Next() |
| 22 | + { |
| 23 | + _rng.GetBytes(_uint32Buffer); |
| 24 | + return BitConverter.ToInt32(_uint32Buffer, 0) & 0x7FFFFFFF; |
| 25 | + } |
| 26 | + |
| 27 | + public Int32 Next(Int32 maxValue) |
| 28 | + { |
| 29 | + if (maxValue < 0) |
| 30 | + throw new ArgumentOutOfRangeException("maxValue"); |
| 31 | + return Next(0, maxValue); |
| 32 | + } |
| 33 | + |
| 34 | + public Int32 Next(Int32 minValue, Int32 maxValue) |
| 35 | + { |
| 36 | + if (minValue > maxValue) |
| 37 | + throw new ArgumentOutOfRangeException("minValue"); |
| 38 | + if (minValue == maxValue) return minValue; |
| 39 | + Int64 diff = maxValue - minValue; |
| 40 | + while (true) |
| 41 | + { |
| 42 | + _rng.GetBytes(_uint32Buffer); |
| 43 | + UInt32 rand = BitConverter.ToUInt32(_uint32Buffer, 0); |
| 44 | + |
| 45 | + Int64 max = (1 + (Int64)UInt32.MaxValue); |
| 46 | + Int64 remainder = max % diff; |
| 47 | + if (rand < max - remainder) |
| 48 | + { |
| 49 | + return (Int32)(minValue + (rand % diff)); |
| 50 | + } |
| 51 | + } |
| 52 | + } |
| 53 | + |
| 54 | + public double NextDouble() |
| 55 | + { |
| 56 | + _rng.GetBytes(_uint32Buffer); |
| 57 | + UInt32 rand = BitConverter.ToUInt32(_uint32Buffer, 0); |
| 58 | + return rand / (1.0 + UInt32.MaxValue); |
| 59 | + } |
| 60 | + |
| 61 | + public void NextBytes(byte[] buffer) |
| 62 | + { |
| 63 | + if (buffer == null) throw new ArgumentNullException("buffer"); |
| 64 | + _rng.GetBytes(buffer); |
| 65 | + } |
| 66 | + } |
| 67 | +} |
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